Patent GB-310945-A (GB)
Title: Improvements in or relating to step by step mechanical movements
IPC: F16H31/00
Filed: 1928-11-05
Abstract: 310,945. Hemphill Co., (Assignees of Lawson, R. H.). May 4, 1928, [Convention date]. Cam mechanism; ratchet gearing.-Comprises a mechanical movement embodying a reciprocatory element movable towards and from a. rotatory element for transmitting step-by-step rotation in either direction thereto and means, such as an automatically controlled slide, for shifting the driving member to one side or the other of the axis of the rotary element to determine the direction of rotation, the driving member reciprocating idly in the central or neutral position. Means may be provided to prevent uncontrolled movement of the rotatory element. The apparatus shown may be applied to jacquard patterning mechanism such as described in Specification 288,256, [Class 74 (ii), Knitting &c.], the movement being utilized to adjust the height of a screw head 98, which may carry or be attached to the jacquard drum. The reciprocatory element 1, universally jointed to a bell-crank 17 rocked by a main reciprocating member 12, is formed with a pointed end 2 which on its forward stroke engages and pushes round pins 38 on the rotatory element 37, this element being mounted on a fixed stud 36 and peripherally toothed to drive a pinion 96 through which the screw support 97 of the head 98 is threaded. At the rear end of its stroke, the element 1 is laterally constrained or set by shoulders 7, 8 thereon engaging uprights 9, 10 on a transversely adjustable guide 11. In the central setting, Fig. 1, the device reciprocates idly. When tilted laterally, as shown in Fig. 10, one of a second pair of shoulders, 72, 73 rides on a fixed cam surface 70 or 71 as the pointed end 2 pushes behind a pin 38. Simultaneously, the pointed end pushes aside a butting surface 82 or 83 on one of a pair of pivoted catches 77, 78 normally drawn, together bya spring 79 to lock the rotary member 37. The lateral adjustments of the slide 11, limited by screw stops 68, 69, are determined by a pattern chain 59 acting through a lever 54, link 48, and bell crank 45, 42 (Fig. 5), the chain being carried. by a sprocket wheel driven through ratchet gearing from the main reciprocating member 12. For this purpose, the bell crank 17 operating the member 1 is secured to a cross shaft 20, to which is also secured a pawl-carrying arm 26, the shaft passing through a fixed bearing sleeve 25, Fig. 7, upon which are loosely mounted the ratchet wheel 29 and sprocket 24 permanently braked by a spring-tensioned strap 32. The pawl 27 on the arm 26 carries a pin 30 whereby it may be lifted out of action by a curved arm 90 operated,. through a cross shaft 91 with a second arm 92 and a connecting rod 94, by suitable means such as cams in the main. patterning mechanism (not shown) of the machine. When reciprocating idly,- the main member 1 may be lifted above the level of the pins 38 by a crosspin 89 on a lever arm 88 operated, through a second arm 86 and connecting rod 85, by any suitable means in the machine. The transverse slide 11 may be automatically brought to the central or neutral position, when the head 98 reaches either limit of its motion, by the action of stops or projections thereon upon a lever 99 having a forked end 103 engaging the arm 45 of the bell crank 42 through which the slide is normallv actuated. To permit such control, the bell-crank is connected to the link 48 by a screw-stud 46 engaging a slot 47, a spring 49 coupling the stud to the lower end 50 of the link. A second spring 51, coupled to the machine frame, tends to raise the link 48, keeping the lever 54 in engagement with, the pattern chain 59.